If you use an if statement wrongly, you get an error message that leads you on a wild goose chase. The problem is not that you are trying to assign a value to anything, it's that the if statement cannot be used alone.

A better error message would be something like: "You wrote 'If player is in Kitchen, say "Hi."' : but it looks like you are trying to create a rule or enforce a condition without declaring a rule in a way that I understand. You can use rule verbs like before, instead, or after; alternately, you can create a rule within a rulebook."

Problem. You wrote 'If player is in Kitchen, say "Hi."' : but this seems to give something a name which contains double-quoted text, which is not allowed. If you do need quotes in a name, one option would be to write something like 'In the Saloon is 'Black' Jacques Bernoulli.'; but this problem message is often caused by an accident in punctuation, in which case you never intended to create an object - you thought that the text ended a sentence because it finished with sentence-ending punctuation, when in fact it didn't, so that I read the next words as following on.

and creates an object (Lindsay Anderson's movie, presumably) and a room, putting one in the other. The problem with the source text was not that a sentence began with "if", it was the problem reported by Inform.

It's arguable that we should leave things as they are, but I've added a footnote to problem messages like this one in cases where control structures appear in assertion sentences known to be erroneous:

>--> The way this sentence starts makes me think it might have been intended as part of a rule rather than being a statement about the the way things are at the beginning of play. For example, 'If the player is in the Penalty Zone, say "An alarm sounds." is not allowed: it has to be put in the form of a rule showing Inform what circumstances apply - for example 'Every turn: if the player is in the Penalty Zone, say "An alarm sounds."